zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/build/uClibc/docs/probe_math_exception.c b/ap/build/uClibc/docs/probe_math_exception.c
new file mode 100644
index 0000000..dbc9020
--- /dev/null
+++ b/ap/build/uClibc/docs/probe_math_exception.c
@@ -0,0 +1,64 @@
+/* Small test program for probing how various math functions
+ * with specific operands set floating point exceptions
+ */
+
+#define _ISOC99_SOURCE 1
+#define _GNU_SOURCE 1
+
+#include <stdint.h>
+#include <math.h>
+#include <fenv.h>
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+ float largest, small, t, inf_float;
+
+ largest = small = 1;
+ while (1) {
+ t = largest + small;
+ /* optimizations may make plain "t == largest" unreliable */
+ if (memcmp(&t, &largest, sizeof(float)) == 0)
+ break;
+ if (isfinite(t)) {
+ largest = t;
+ small *= 2;
+ continue;
+ }
+ small /= 2;
+ }
+ inf_float = largest + largest;
+ //printf("%.40g ", largest);
+ //printf("[%llx]\n", (long long) (*(uint32_t *)&largest));
+
+ feclearexcept(FE_ALL_EXCEPT);
+
+ //t = 1.0 / 0.0; // simple test: FE_DIVBYZERO
+ //t = nextafterf(largest, 1); // glibc 2.8: no math exceptions raised
+ //t = nextafterf(largest, largest); // glibc 2.8: no math exceptions raised
+ //t = nextafterf(largest, inf_float); // glibc 2.8: FE_INEXACT FE_OVERFLOW
+
+#define PREX(ex) do { if (fetestexcept(ex)) printf(#ex " "); } while(0)
+#ifdef FE_INEXACT
+ PREX(FE_INEXACT);
+#endif
+#ifdef FE_DIVBYZERO
+ PREX(FE_DIVBYZERO);
+#endif
+#ifdef FE_UNDERFLOW
+ PREX(FE_UNDERFLOW);
+#endif
+#ifdef FE_OVERFLOW
+ PREX(FE_OVERFLOW);
+#endif
+#ifdef FE_INVALID
+ PREX(FE_INVALID);
+#endif
+ if (fetestexcept(FE_ALL_EXCEPT))
+ printf("\n");
+ else
+ printf("no math exceptions raised\n");
+
+ printf("%.40g\n", t);
+ return 0;
+}